Does this have to do with the Safety Ballast Tank or is it in reference to something else?

If it does deal with the Safety Ballast Tank, I am still confused as to what this command really means and why you would do it.

The Safety Ballast Tank is a small pressure resistant ballast tank located amidships between the Fuel Ballast Tanks and the Auxiliary Ballast Tanks.

The technical book “The Fleet Type Submarine” states:

“The primary function of the safety tank is to provide a means for quickly regaining positive buoyancy by blowing the tank when submerged. It follows, then, that the safety tank must be fully flooded when submerged, otherwise it can not fulfill its primary purpose”

I can understand that in order to surface very rapidly, the Safety Ballast Tank can be blown. Or if the conning tower or main induction is flooded, the Safety Ballast Tank can be used to compensate for the extra water weight.

What does “Put a bubble in Safety” mean?

Does it mean that a small quantity of air is blown into the Safety Ballast Tank? If so why?

Is the command not to be taken so literally and “put a bubble in Safety” means something else to do with the Safety Ballast Tank? If so what?

Is this not even a real command but some hollywood BS?

Landlubber minds want to know

__________________abusus non tollit usum - A right should NOT be withheld from people on the basis that some tend to abuse that right.

Put a bubble in safety... We might need to purge completely if the flooding continues. Blow her gently so as not to allow the enemy sonar operators the oppertunity to hear the roar of a balleast tank purge.

The safety enabled a small differential in bouyancy that floated the sub positive yet allowed planes and velocity to keep the vessel submerged at commanded depth without having to blow the main tanks. In combination with the comand flood negative or blow negative, the boyancy of a boat is more readily maintained and controllable. Often the boats bouyancy balance was crucial in an attack approach and setup against a listening adversary. With out these crucial settings the blowing of tanks is a noisy affair and can often warn an enemy surface combatant not only as to where you are but what you are doing. Ideal neutral bouyancy was a constant balancing act with temeprature, salinity, and operating depth all factors.
A limited compressed air supply could be extended if a boat was primarily running slight positive bouyancy and using planes and velocity for depth maintenance. Only in emergencies and crash dives would one open all the bllast tanks and take on the tons of water to claw down to the deep and silent world of submerged safety. The captain and crew that did this imprudently or did so with holed or leaking tanks are mostly still out here on permanent patrol.

So "put a bubble in safety" means to get the boat to positive or near postive bouyancy so that the planes, forward velocity, an a slight purge of the main tanks would send her back up to the surface realm. Once at the surface low preassure turbo blowers would charge the main tanks and float the sub above the water...

An intial surface condition often had little freeboard unless the captain and crew were sure they could recharge their air they used to blow....

The title "Wir Fahren auf England" is sung by the Teutonic Titwillow Lilly Von Shtup, in "Blazing Saddles". Your signature uses the word "gegen" which means against... Implying a condition of war or strife...

Look for it when Mel Brooks best hits your screen next time... It was a WWI era song...

Thanks for the kind words..

Here is a list of the many tanks aboard a sub... Note the Safety tank

Main ballast tanks - Tanks that are provided primarily to furnish buoyancy when the vessel is in surface condition and that are habitually carried completely filled when the vessel is submerged.Variable ballast tanks - Ballast tanks that are not habitually carried completely filled when submerged and whose contents may be varied to provide weight compensation are known as variable ballast tanks. These ballast tanks are constructed to withstand full sea pressure.Negative tank - The Negative Tank is a variable ballast tank providing negative buoyancy and initial down-angle. Submarines normally will operate submerged in neutral buoyancy and without trim when the negative tank is nearly empty. It is used to reduce the time required in submerging from surface condition, to reduce the time required to increase depth while operating submerged, and to prevent broaching when decreasing depth. It may be blown or pumped.Safety tank - The Safety Tank is a heavily reinforced main ballast tank arranged to permit pumping as well as quick blowing to regain positive buoyancy. Under normal submerged conditions, the blowing or pumping of this tank will bring the conning tower above the surface.Bow buoyancy tank - The Bow Buoyancy Tank is a free-flooding vent-controlled tank with its main volume above the normal surface waterline. It is located in the extreme bow of the vessel and is formed of the plating of the superstructure. Its function is to provide reserve surface buoyancy, emergency positive buoyancy in the submerged condition, and to aid in surfacing.Auxiliary tanks - The auxiliary tanks are variable ballast tanks located at or near the submerged center of buoyancy, and are used to vary the over-all trim of the boat.Trim tanks - The trim tanks are the variable ballast tanks nearest the bow and stern of the boat and are used to provide fore-and-aft compensation.Normal fuel oil tanks - Tanks designed solely for containing the engine fuel oil are known as normal fuel oil tanks. Note that because fuel tanks are located outside the pressure hull and cannot withstand the pressure of the sea during a dive they must always be completely filled with fluid. As fuel is withdrawn from these tanks it is replaced with sea water. The remaining fuel oil floats on this compensating water so fuel is withdrawn for use from the top of the tank. Remaining fuel quantity is determined by locating the oil/water interface (via tubing installed in the tanks) and then calculating fuel volume from the tank geometry.Fuel ballast tanks - The fuel ballast tanks are designed to be utilized as fuel oil tanks for increased operating range. When empty, they may be converted to main ballast tanks, providing additional freeboard and thereby increasing surface speed through decreased drag.Expansion tank - The Expansion Tank, connected between the head box and the compensating water main, admits sea pressure to the fuel oil tanks. It receives any overflow from the fuel tanks resulting either from overfilling the fuel system or from temperature expansion. The bilges are pumped into this tank to prevent leaving an oil slick or polluting a harbor.

Collecting tank - The Collecting Tank, connected to the fuel oil tanks through the fuel transfer line, serves as a water and sediment trap for the fuel oil being transferred to the fuel pump. Clean fuel oil tanks - The clean fuel oil tanks are storage tanks located within the pressure hull. They receive clean fuel oil from the purifiers and are the supply tanks from which the engines receive their clean fuel. Poppet valve drain tank - The two poppet valve drain tanks are located under the platform deck of the fore and aft torpedo rooms immediately below the breech of the torpedo tubes. The air and water from the poppet valves, incident to the firing of torpedoes, is discharged into these tanks.Fresh water tanks - The fresh water tanks contain potable water for drinking, cooking, and certain sanitary facilities.Battery fresh water tanks - The battery fresh water tanks are storage tanks for the distilled water used in watering the main storage batteries.Sanitary tanks - The sanitary tanks receive and store the ship's sanitary drainage until conditions permit overboard discharge.WRT tanks - The WRT (Water 'Round Torpedo) tanks are variable ballast tanks located in the forward and after torpedo rooms for flooding or draining the torpedo tubes. When a torpedo is fired the slug of sea water that replaces the fired torpedo in the tube will approximately equal the weight of the torpedo that just left the boat, and this water is drained into the WRT so that the tube may be opened and reloaded, and thus maintaining trim. When torpedoes are loaded aboard sufficient water is pumped from the WRT tanks to balance the weight of the topedoes.

The title "Wir Fahren auf England" is sung by the Tutonic Titmouse Lilly, in "Blazing Saddles".

Try to picture a Lilly von Schtupp accent as she says "Teutonic Titwillow".

__________________"Voice or no voice, the people can always be brought to the bidding of the leaders. This is easy. All you have to do is tell them they are being attacked, and denounce the pacifists for lack of patriotism and for exposing the country to danger. It works the same in any country."
--Hermann Göring